The present invention is directed to a tubular conduit or the like fabricated from a plurality of tubes or pipes.
There is disclosed in Applicant's prior U.S. Pat. No. 3,538,955 dated Nov. 10, 1970, the concept of suspended submarine pipe consisting of a plurality of small tubes or pipes that are so assembled and joined to one another as to form a relatively large diameter pipe. In said patent the wall of the large diameter pipe is constructed from a plurality of sealed tubes or pipes arranged parallel to each other with their axes parallel to the axis of the large pipe and sealed to one another along their lengths. The small tubes or pipes are provided with an encircling stiffening ring for the purpose of keeping said tubes and pipes in alignment in a circle.
When the large pipe is submerged and supported from its upper end the buoyant force, as produced by the small tubes or pipes, reduces the tensile stresses in the pipe wall. The buoyancy of the small tubes or pipes may be varied by varying the density of the material in the tubes as by filling the tubes with gases.